Summary of February 2011 Monthly Hydrologic Conditions

February 2011

Precipitation was above normal at the Newark and Atlantic City index stations, and below normal at the Trenton index station. Newark reported 3.49 inches, which is 118 percent of normal. Atlantic City reported 2.93 inches, which is 103 percent of normal. Trenton reported 2.54 inches, which is 91.04 percent of normal. Total precipitation over the past 12 months was: 44.22 inches at Newark, which is -2.03 inches below normal; 39.01 inches at Atlantic City, which is -1.58 inches below normal; and 38.73 inches at Trenton, which is -2.66 inches below normal.

Combined storage in the thirteen major water supply reservoirs as of February 28 was 70.267 billion gallons (86.9 percent of capacity), which is higher than the average February contents for the reference period 1961-1990. The storage was 6.730 billion gallons more than one month ago and -4.383 billion gallons less than one year ago. The thirteen major water supply reservoirs are as follows: Lake Tappan, Woodcliff Lake, Oradell Reservoir, DeForest Lake, Splitrock Reservoir, Boonton Reservoir, Canistear Reservoir, Oak Ridge Reservoir, Clinton Reservoir, Charlotteburg Reservoir, Echo Lake, Wanaque Reservoir and Spruce Run Reservoir.

Streamflow was below the long-term monthly-mean for the reference period 1971-2000 at all three index stations. The monthly-mean discharge at South Branch Raritan River near High Bridge was 142 ft3/s, 83.5 percent of the long-term mean. The monthly-mean discharge of the Great Egg Harbor River at Folsom was 107 ft3/s, 100 percent of the long-term mean. The monthly mean discharge of the Delaware River at Trenton was 10590 ft3/s, 75.8 percent of the long-term mean. The observed daily mean discharge of the Delaware River at Trenton on February 28 was 22700 ft3/s.

Groundwater levels, as measured in water-table observation wells for the month of February, were above normal at all three index wells. Levels increased from last month. Levels were higher than one year ago at the Readington School 11 and Morrell 1 index wells, but Lower than one year ago at the Vocational School 2 index well.

Water temperature and dissolved oxygen data collected from the Delaware River at Trenton were within recorded historical monthly extremes. A specific conductance reading of 385 microsiemens per centimeter at 25°C was a new recorded high for February. It exceeded the previous historic high of 377 microsiemens per centimeter at 25°C for February. Water temperature ranged from 0.0 to 4.5 degrees Celsius. Dissolved oxygen ranged from 13.4 to 17.9 milligrams per liter. Specific conductance ranged from 200 to 385 microsiemens per centimeter at 25°C.

Note: The preceding data is preliminary and subject to revision.

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